1. Technical Field
The present invention relates to a piezoelectric device including an electronic part and a piezoelectric resonator on a substrate and to a method for manufacturing the piezoelectric device.
2. Related Art
Piezoelectric devices are widely used in hard disk drives (HDDs), mobile computers, or small-size information equipment such as IC cards, mobile phones or car telephones, or mobile communication devices such as a paging system.
FIG. 12 is a partially cutout lateral view showing the internal structure of a conventional piezoelectric device 1. (See JP-A-2002-64333).
The piezoelectric device 1 shown in FIG. 12 has a substrate 2, an electronic part 3 and a piezoelectric resonator 4.
A stud member 7 is installed on the upper surface of the substrate 2. The piezoelectric resonator 4 is mounted on the stud member 7. Space S is formed between the piezoelectric resonator 4 and the substrate 2. The electronic part 3 is arranged in the space S.
The substrate 2 has on its upper surface an electrode terminal portion 6 electrically connected to a mounting terminal 5. The electrode terminal portion 6a and the electronic part 3 are electrically connected to each other.
The electronic part 3 and the piezoelectric resonator 4 are electrically connected to each other by a wiring pattern 8 provided on the stud member 7.
As described above, the entire width of the piezoelectric device 1 is substantially equal to the width of the piezoelectric resonator 4 by arranging the electronic part 3 under the piezoelectric resonator 4, thereby achieving reduction in mounting area.
JP-A-2002-64333 is an example of related art.
Recently, rapid development of thickness reduction is observed in electronic devices such as information devices. Reduction in thickness is also required for piezoelectric devices used in those electronic devices.
On the other hand, it is indeed possible to reduce the mounting area of the piezoelectric device 1 shown in FIG. 12, for example. However, the dimension in the height direction must be large because the substrate 2, the electronic part 3 and the piezoelectric resonator 4 are stacked in the height direction. As a result, it is impossible for the piezoelectric device 1 to fill the requirement of reduction in thickness.